Borderless Display With Light-Bending Structures

ABSTRACT

An electronic device may be provided with a display mounted in a housing. The display may have an array of display pixels that provide image light to a user. The array of display pixels may form an active display structure with a rectangular shape. The rectangular active display structure may be surrounded by an inactive border region. Optical structures such as a sheet of glass or another optical member may have portions that are configured to bend light from the display pixels along the periphery of the active display structure. The optical member may have an area that is larger than the area of the active display structure, so that the presence of the optical member may serve to enlarge the apparent size of the display. Solidified liquid polymer may be used to support the optical structures and may be interposed between the optical structures and the active display structures.

This application is a continuation of U.S. patent application Ser. No.15/234,955, filed Aug. 11, 2016, which is a continuation of U.S. patentapplication Ser. No. 13/631,024, filed Sep. 28, 2012, which are herebyincorporated by reference herein in their entireties.

BACKGROUND

This relates generally to electronic devices, and more particularly, toelectronic devices with displays.

Electronic devices often include displays. For example, cellulartelephones and portable computers often include displays for presentinginformation to a user. An electronic device may have a housing such as ahousing formed from plastic or metal. Components for the electronicdevice such as display components may be mounted in the housing.

It can be challenging to incorporate a display into the housing of anelectronic device. Size and weight are often important considerations indesigning electronic devices. If care is not taken, displays may bebulky or may be surrounded by overly large borders. The housing of anelectronic device can be adjusted to accommodate a bulky display withlarge borders, but this can lead to undesirable enlargement of the sizeand weight of the housing and unappealing device aesthetics.

It would therefore be desirable to be able to provide improved displaysfor electronic devices.

SUMMARY

An electronic device may be provided with a display. The display may bemounted in a housing. The display may have an array of display pixelsthat provide image light to a user. Display pixels may be organiclight-emitting diode pixels, may be backlit liquid crystal displaypixels, or may be display pixels of other types.

The array of display pixels may form an active display structure with arectangular shape. The rectangular active display structure may besurrounded by an inactive display structure border region. Opticalstructures such as a sheet of glass or other optical member may haveportions that are configured to bend light from the display pixels thatare located along the periphery of the active display structure.

The optical member may have an area that is larger than area of theactive display structure. The presence of the optical member and theportions of the optical member that are configured to bend the light mayserve to enlarge the apparent size of the display. Solidified liquidpolymer may be used to support the optical structures and may beinterposed between the optical structures and the active displaystructures. A display cover layer may overlap the optical member. Atouch sensor and coating layers may be included in the display.

Further features of the invention, its nature and various advantageswill be more apparent from the accompanying drawings and the followingdetailed description of the preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an illustrative electronic device suchas a laptop computer with a display in accordance with an embodiment ofthe present invention.

FIG. 2 is a perspective view of an illustrative electronic device suchas a handheld electronic device with a display in accordance with anembodiment of the present invention.

FIG. 3 is a perspective view of an illustrative electronic device suchas a tablet computer with a display in accordance with an embodiment ofthe present invention.

FIG. 4 is a schematic diagram of an illustrative electronic device witha display in accordance with an embodiment of the present invention.

FIG. 5 is a cross-sectional side view of an illustrative display inaccordance with an embodiment of the present invention.

FIG. 6 is a top view of illustrative display layers in a display havingan active region with an array of display pixels and an inactive borderregion in accordance with an embodiment of the present invention.

FIG. 7 is a diagram showing how a mold may be used to form displaystructures such as glass structures with curved surfaces in accordancewith an embodiment of the present invention.

FIG. 8 is a diagram showing how a slumping process may be used to formdisplay structures such as glass structures with curved surfaces inaccordance with an embodiment of the present invention.

FIG. 9 is a diagram showing how a machining process may be used to formdisplay structures such as glass structures with curved surfaces inaccordance with an embodiment of the present invention.

FIG. 10 is a cross-sectional side view of an illustrative display with aglass layer having a curved portion along the edge of a lower surfacefor bending light produced by an array of display pixels and therebycreating a borderless appearance for the display in accordance with anembodiment of the present invention.

FIG. 11 is a cross-sectional side view of an illustrative display with aglass layer having curved upper and lower surfaces along the edge of theglass layer for bending light produced by an array of display pixels andthereby creating a borderless appearance for the display in accordancewith an embodiment of the present invention.

FIG. 12 is a cross-sectional side view of an illustrative display with aglass layer having a convex curved upper surface for bending lightproduced by an array of display pixels and thereby creating a borderlessappearance for the display in accordance with an embodiment of thepresent invention.

FIG. 13 is a cross-sectional side view of an illustrative display with aglass layer having edges with curved upper surfaces for bending lightproduced by an array of display pixels and thereby creating a borderlessappearance for the display in accordance with an embodiment of thepresent invention.

FIG. 14 is a cross-sectional side view of an illustrative display with aglass layer having edges with curved upper surfaces for bending lightproduced by an array of display pixels that is separated from the glasslayer by a gap and thereby creating a borderless appearance for thedisplay in accordance with an embodiment of the present invention.

FIG. 15 is a cross-sectional side view of an illustrative display with aglass layer having a convex curved upper surface for bending lightproduced by an array of display pixels that is separated from the glasslayer by a gap and thereby creating a borderless appearance for thedisplay in accordance with an embodiment of the present invention.

FIG. 16 is a cross-sectional side view of an illustrative display with adisplay cover layer and optical structures with angled surfaces forbending light produced by an array of display pixels and therebycreating a borderless appearance for the display in accordance with anembodiment of the present invention.

FIG. 17 is a cross-sectional side view of an illustrative display with aglass layer that is covered with one or more coating layers and that hasan upper surface with curved edge regions for bending light produced byan array of display pixels and thereby creating a borderless appearancefor the display in accordance with an embodiment of the presentinvention.

FIG. 18 is a cross-sectional side view of an illustrative display havinga glass layer with a curved upper surface for bending light produced byan array of display pixels and having a layer of clear material such assolidified liquid polymer interposed between the glass layer and arrayof display pixels in accordance with an embodiment of the presentinvention.

FIG. 19 is a cross-sectional side view of an illustrative display havinga glass layer with a curved lower surface for bending light produced byan array of display pixels and having a layer of clear material such assolidified liquid polymer interposed between the glass layer and arrayof display pixels in accordance with an embodiment of the presentinvention.

FIG. 20 is a cross-sectional side view of an illustrative display havinga glass layer with a curved surface for bending light produced by anarray of display pixels and having a planar display cover layer inaccordance with an embodiment of the present invention.

FIG. 21 is a cross-sectional side view of an illustrative display havinga glass layer with a curved surface for bending light produced by anarray of display pixels and having a touch sensor located on a lowersurface of the glass layer in accordance with an embodiment of thepresent invention.

FIG. 22 is a cross-sectional side view of an illustrative display havinga glass layer with a curved surface for bending light produced by anarray of display pixels and having a touch sensor located on an uppersurface of the array of display pixels in accordance with an embodimentof the present invention.

FIG. 23 is a cross-sectional side view of an illustrative display havinga glass layer with a curved surface for bending light produced by anarray of display pixels and having a touch sensor located on an uppersurface of the glass layer in accordance with an embodiment of thepresent invention.

FIG. 24 is a cross-sectional side view of an illustrative display havinga glass layer with a curved surface for bending light produced by anarray of display pixels and having a touch sensor located on an uppersurface of the glass layer under an associated display cover layer inaccordance with an embodiment of the present invention.

FIG. 25 is a cross-sectional side view of an illustrative display havinga glass layer with a curved surface for bending light produced by anarray of display pixels and having a touch sensor located on a lowersurface of an associated display cover layer in accordance with anembodiment of the present invention.

DETAILED DESCRIPTION

Electronic devices may include displays. The displays may be used todisplay images to a user. Illustrative electronic devices that may beprovided with displays are shown in FIGS. 1, 2, and 3.

FIG. 1 shows how electronic device 10 may have the shape of a laptopcomputer having upper housing 12A and lower housing 12B with componentssuch as keyboard 16 and touchpad 18. Device 10 may have hinge structures20 that allow upper housing 12A to rotate in directions 22 aboutrotational axis 24 relative to lower housing 12B. Display 14 may bemounted in upper housing 12A. Upper housing 12A, which may sometimesreferred to as a display housing or lid, may be placed in a closedposition by rotating upper housing 12A towards lower housing 12B aboutrotational axis 24.

FIG. 2 shows how electronic device 10 may be a handheld device such as acellular telephone, music player, gaming device, navigation unit, orother compact device. In this type of configuration for device 10,housing 12 may have opposing front and rear surfaces. Display 14 may bemounted on a front face of housing 12. Display 14 may, if desired, havea display cover layer or other exterior layer that includes openings forcomponents such as button 26. Openings may also be formed in a displaycover layer or other display layer to accommodate a speaker port (see,e.g., speaker port 28 of FIG. 2).

FIG. 3 shows how electronic device 10 may be a tablet computer. Inelectronic device 10 of FIG. 3, housing 12 may have opposing planarfront and rear surfaces. Display 14 may be mounted on the front surfaceof housing 12. As shown in FIG. 3, display 14 may have a cover layer orother external layer with an opening to accommodate button 26 (as anexample).

The illustrative configurations for device 10 that are shown in FIGS. 1,2, and 3 are merely illustrative. In general, electronic device 10 maybe a laptop computer, a computer monitor containing an embeddedcomputer, a tablet computer, a cellular telephone, a media player, orother handheld or portable electronic device, a smaller device such as awrist-watch device, a pendant device, a headphone or earpiece device, orother wearable or miniature device, a television, a computer displaythat does not contain an embedded computer, a gaming device, anavigation device, an embedded system such as a system in whichelectronic equipment with a display is mounted in a kiosk or automobile,equipment that implements the functionality of two or more of thesedevices, or other electronic equipment.

Housing 12 of device 10, which is sometimes referred to as a case, maybe formed of materials such as plastic, glass, ceramics, carbon-fibercomposites and other fiber-based composites, metal (e.g., machinedaluminum, stainless steel, or other metals), other materials, or acombination of these materials. Device 10 may be formed using a unibodyconstruction in which most or all of housing 12 is formed from a singlestructural element (e.g., a piece of machined metal or a piece of moldedplastic) or may be formed from multiple housing structures (e.g., outerhousing structures that have been mounted to internal frame elements orother internal housing structures).

Display 14 may be a touch sensitive display that includes a touch sensoror may be insensitive to touch. Touch sensors for display 14 may beformed from an array of capacitive touch sensor electrodes, a resistivetouch array, touch sensor structures based on acoustic touch, opticaltouch, or force-based touch technologies, or other suitable touch sensorcomponents.

Displays for device 10 may, in general, include image pixels formed fromlight-emitting diodes (LEDs), organic LEDs (OLEDs), plasma cells,electrowetting pixels, electrophoretic pixels, liquid crystal display(LCD) components, or other suitable image pixel structures. In somesituations, it may be desirable to use LCD components to form display14, so configurations for display 14 in which display 14 is a liquidcrystal display are sometimes described herein as an example. It mayalso be desirable to provide displays such as display 14 with backlightstructures, so configurations for display 14 that include a backlightunit may sometimes be described herein as an example. Other types ofdisplay technology may be used in device 10 if desired. The use ofliquid crystal display structures and backlight structures in device 10is merely illustrative.

A display cover layer may cover the surface of display 14 or a displaylayer such as a color filter layer or other portion of a display may beused as the outermost (or nearly outermost) layer in display 14. Adisplay cover layer or other outer display layer may be formed from atransparent glass sheet, a clear plastic layer, or other transparentstructures.

Touch sensor components such as an array of capacitive touch sensorelectrodes formed from transparent materials such as indium tin oxidemay be formed on the underside of a display cover layer, may be formedon a separate display layer such as a glass or polymer touch sensorsubstrate, or may be integrated into other display layers (e.g.,substrate layers such as a thin-film transistor layer).

A schematic diagram of an illustrative configuration that may be usedfor electronic device 10 is shown in FIG. 4. As shown in FIG. 4,electronic device 10 may include control circuitry 29. Control circuitry29 may include storage and processing circuitry for controlling theoperation of device 10. Control circuitry 29 may, for example, includestorage such as hard disk drive storage, nonvolatile memory (e.g., flashmemory or other electrically-programmable-read-only memory configured toform a solid state drive), volatile memory (e.g., static or dynamicrandom-access-memory), etc. Control circuitry 29 may include processingcircuitry based on one or more microprocessors, microcontrollers,digital signal processors, baseband processors, power management units,audio codec chips, application specific integrated circuits, etc.

Control circuitry 29 may be used to run software on device 10, such asoperating system software and application software. Using this software,control circuitry 29 may present information to a user of electronicdevice 10 on display 14. Display 14 may contain an array of displaypixels (e.g., liquid crystal display pixels) that are organized in rowsand columns. Control circuitry 29 may be used to display content for auser of device 10 on the array of display pixels in display 14.

Input-output circuitry 30 may be used to allow data to be supplied todevice 10 and to allow data to be provided from device 10 to externaldevices. Input-output circuitry 30 may include communications circuitry32. Communications circuitry 32 may include wired communicationscircuitry for supporting communications using data ports in device 10.Communications circuitry 32 may also include wireless communicationscircuits (e.g., circuitry for transmitting and receiving wirelessradio-frequency signals using antennas).

Input-output circuitry 30 may also include input-output devices 34. Auser can control the operation of device 10 by supplying commandsthrough input-output devices 34 and may receive status information andother output from device 10 using the output resources of input-outputdevices 34.

Input-output devices 34 may include sensors and status indicators 36such as an ambient light sensor, a proximity sensor, a temperaturesensor, a pressure sensor, a magnetic sensor, an accelerometer, andlight-emitting diodes and other components for gathering informationabout the environment in which device 10 is operating and providinginformation to a user of device 10 about the status of device 10.

Audio components 38 may include speakers and tone generators forpresenting sound to a user of device 10 and microphones for gatheringuser audio input.

Display 14 (e.g., the array of display pixels in display 14) may be usedto present images for a user such as text, video, and still images.Sensors 36 may include a touch sensor array that is formed as one of thelayers in display 14.

User input may be gathered using buttons and other input-outputcomponents 40 such as touch pad sensors, buttons, joysticks, clickwheels, scrolling wheels, touch sensors such as sensors 36 in display14, key pads, keyboards, vibrators, cameras, and other input-outputcomponents.

A cross-sectional side view of an illustrative configuration that may beused for display 14 of device 10 (e.g., for display 14 of the devices ofFIG. 1, FIG. 2, or FIG. 3 or other suitable electronic devices) is shownin FIG. 5. As shown in FIG. 5, display 14 may include backlightstructures such as backlight unit 42 for producing backlight 44. Duringoperation, backlight 44 travels outwards (vertically upwards indimension Z in the orientation of FIG. 5) and passes through displaypixel structures in display layers 46. This illuminates any images thatare being produced by the display pixels for viewing by a user. Forexample, backlight 44 may illuminate images on display layers 46 thatare being viewed by viewer 48 in direction 50.

Display 14 may, if desired, have one or more optical structures that arelocated above display layers 46. For example, display 14 may have adisplay cover layer such as display cover layer 84. Display cover layer84 may be formed from a layer of clear glass, a transparent sheet ofplastic, or other transparent structure. Display cover layer 84 may bemounted in housing 12 (e.g., using housing sidewalls). During operation,light 44 may pass through the array of display pixels formed fromdisplay layers 46 and display cover layer 84 for viewing by user 48.

Display layers 46 may be mounted in chassis structures such as a plasticchassis structure and/or a metal chassis structure to form a displaymodule for mounting in housing 12 or display layers 46 may be mounteddirectly in housing 12 (e.g., by stacking display layers 46 into arecessed portion in housing 12). Display layers 46 may form a liquidcrystal display or may be used in forming displays of other types.Display layers 46 may sometimes be referred to as a display module, adisplay, or an array of display pixels. The image light (light 44) thatpasses through the array of display pixels is used in displaying contenton display 14 for user 48.

In a configuration in which display layers 46 are used in forming aliquid crystal display, display layers 46 may include a liquid crystallayer such a liquid crystal layer 52. Liquid crystal layer 52 may besandwiched between display layers such as display layers 58 and 56.Layers 56 and 58 may be interposed between lower polarizer layer 60 andupper polarizer layer 54.

Layers 58 and 56 may be formed from transparent substrate layers such asclear layers of glass or plastic. Layers 56 and 58 may be layers such asa thin-film transistor layer and/or a color filter layer. Conductivetraces, color filter elements, transistors, and other circuits andstructures may be formed on the substrates of layers 58 and 56 (e.g., toform a thin-film transistor layer and/or a color filter layer). Touchsensor electrodes may also be incorporated into layers such as layers 58and 56 and/or touch sensor electrodes may be formed on other substrates.

With one illustrative configuration, layer 58 may be a thin-filmtransistor layer that includes an array of thin-film transistors andassociated electrodes (display pixel electrodes) for applying electricfields to liquid crystal layer 52 and thereby displaying images ondisplay 14. Layer 56 may be a color filter layer that includes an arrayof color filter elements for providing display 14 with the ability todisplay color images. If desired, layer 58 may be a color filter layerand layer 56 may be a thin-film transistor layer.

During operation of display 14 in device 10, control circuitry 29 (e.g.,one or more integrated circuits such as components 68 on printed circuit66 of FIG. 5) may be used to generate information to be displayed ondisplay 14 (e.g., display data). The information to be displayed may beconveyed from circuitry 68 to display control circuitry such as displaydriver integrated circuit 62 using a signal path such as a signal pathformed from conductive metal traces in flexible printed circuit 64 (asan example).

Display driver integrated circuit 62 may be mounted onthin-film-transistor layer driver ledge 82 or elsewhere in device 10.During operation of display 14, display driver circuitry 62 and/or otherdisplay control circuitry such as gate driver circuitry formed onsubstrate 58 or coupled to substrate 58 may be used in controlling thearray of display pixels in layers 46 (e.g., using a grid of verticaldata lines and horizontal gate lines).

A flexible printed circuit cable such as flexible printed circuit 64 maybe used in routing signals between printed circuit 66 andthin-film-transistor layer 58. If desired, display driver integratedcircuit 62 may be mounted on printed circuit 66 or flexible printedcircuit 64. Printed circuit 66 may be formed from a rigid printedcircuit board (e.g., a layer of fiberglass-filled epoxy) or a flexibleprinted circuit (e.g., a flexible sheet of polyimide or other flexiblepolymer layer).

Backlight structures 42 may include a light guide plate such as lightguide plate 78. Light guide plate 78 may be formed from a transparentmaterial such as clear glass or plastic. During operation of backlightstructures 42, a light source such as light source 72 may generate light74. Light source 72 may be, for example, an array of light-emittingdiodes.

Light 74 from light source 72 may be coupled into edge surface 76 oflight guide plate 78 and may be distributed in dimensions X and Ythroughout light guide plate 78 due to the principal of total internalreflection. Light guide plate 78 may include light-scattering featuressuch as pits or bumps. The light-scattering features may be located onan upper surface and/or on an opposing lower surface of light guideplate 78.

Light 74 that scatters upwards in direction Z from light guide plate 78may serve as backlight 44 for display 14. Light 74 that scattersdownwards may be reflected back in the upwards direction by reflector80. Reflector 80 may be formed from a reflective material such as alayer of white plastic or other shiny materials.

To enhance backlight performance for backlight structures 42, backlightstructures 42 may include optical films 70. Optical films 70 may includediffuser layers for helping to homogenize backlight 44 and therebyreduce hotspots, compensation films for enhancing off-axis viewing, andbrightness enhancement films (also sometimes referred to as turningfilms) for collimating backlight 44. Optical films 70 may overlap theother structures in backlight unit 42 such as light guide plate 78 andreflector 80. For example, if light guide plate 78 has a rectangularfootprint in the X-Y plane of FIG. 5, optical films 70 and reflector 80may have a matching rectangular footprint. Display layers 46 and theother display structures of FIG. 5 typically have rectangular shapeswith four peripheral edges, but display configurations with other shapesmay be used in forming display 14 if desired.

As shown in FIG. 6, display structures 46 of display 14 may include aplurality of display pixels 86. Display pixels 86 may be organized inrows and columns. Display control circuitry may be used in controllingthe operation of display pixels 86 using signal lines such as data lines88 and gate lines 90. In liquid crystal displays, display pixels 86 mayeach contain an electrode for applying an electric field to anassociated portion of liquid crystal layer 52 (FIG. 5) and a thin-film(amorphous silicon or polysilicon) transistor for controlling themagnitude of the signal applied to the electrode and therefore themagnitude of the electric field. In other types of displays, displaypixels 86 may be formed from other types of structures (e.g., organiclight-emitting diodes, etc.).

Lines 90 may be coupled to the gates of the thin-film transistors andmay sometimes be referred to as gate lines. Lines 88 may be coupled tothe sources of the thin-film transistors and may sometimes be referredto as source lines or data lines. Gate driver circuitry (e.g., thin-filmtransistor gate driver circuitry) may be coupled to gate lines 90.Display driver circuitry that produces data signals for lines 88 (e.g.,a display driver integrated circuit) may be coupled to data lines 88.

Gate driver circuitry, one or more display driver integrated circuits,traces for distributing gate and data signals and other display controlsignals, and other display control circuitry may be formed in inactiveregion 461 of display 14 and display structures 46. As an example, adisplay driver integrated circuit may be mounted along the upper segmentof inactive region 461, whereas gate driver thin-film circuitry may beformed along the left and right segments of inactive region 461. Duringoperation of display 14, display pixels 86 may display images for auser, so the portion of display structures 46 containing display pixels86 may sometimes be referred to as active display structures or theactive area of display 14. The metal traces and other display controlcircuit structures in inactive region 461 do not display any images, sothis portion of structures 46 may sometimes be referred to as inactivedisplay structures.

Inactive region 461 may form a border that surrounds some or all ofactive area 46A. For example, inactive region 461 may have a rectangularring shape of the type shown in FIG. 6 having opposing upper and lowerborder segments and left and right border segments. To provide display14 with a borderless appearance, display 14 may be provided with opticalstructures such as glass layers with curved or angled surfaces. Theoptical structures may be configured to bend and therefore guide lightthat is emitted from the array of display pixels 86 in active area 46Ainto a portion of display 14 that overlaps inactive area 461. By usingoptical structures to bend light from active area 46A, content may bedisplayed in portions of display 14 that overlap inactive regions 461,providing display 14 with a borderless or near borderless appearance.

The optical structures that are used to enhance the apparent size ofdisplay 14 may be formed from transparent materials such as clear glassor plastic structures. As an example, the optical structures may beformed from sheets of clear glass or plastic material or from glass,plastic, or other transparent material of other shapes. Opticalstructures with curved surfaces for bending light may be formed usingmolding equipment, slumping equipment, machining equipment, or othertools for shaping clear material.

FIG. 7 is a diagram showing how a mold may be used to form opticalstructures with curved surfaces for bending light in display 14. Asshown in FIG. 7, molding equipment 92 may include mold structures suchas upper mold structures 94 and lower mold structures 98. Structuressuch as mold structures 94 and 98 may be heated. Optical material 102(e.g., glass, plastic, ceramic, etc.) may be molded between the opposingsurfaces of mold structures 94 and 98 (e.g., when upper mold structure94 is moved in direction 96 and/or when lower mold structures 98 ismoved in direction 100). If desired, molding operations may also involveinjection molding techniques. By molding material 102 with moldingequipment 92, optical structures 104 that have curved or angle surfacesmay be formed.

As shown in the illustrative configuration of FIG. 8, a slumping processmay be used in forming optical structures with curved surfaces forbending light in display 14. Slumping equipment 106 may include a heatedmetal structure or other equipment with exposed curved surfaces such ascurved surface 110. Optical material 108 (e.g., glass, plastic, ceramic,etc.) may be placed on top of surface 110 while slumping equipment 106is heated. When equipment 106 reaches a sufficiently high temperature,optical material 108 will slump under its own weight, thereby creatingoptical structures with curved surfaces such as optical structures 112.Following cooling, structures 112 may be removed from slumping equipment106. As shown on the right-hand side of FIG. 8, the resulting shape foroptical structures 112 may have curved surfaces such as curved uppersurface 114 and curved lower surface 116.

FIG. 9 is a diagram showing how a machining process may be used to formdisplay structures such as glass structures with curved surfaces. Asshown in FIG. 9, optical material 130 may be processed using machiningequipment 118. Machining equipment 118 may have a machining head such ashead 124 (e.g., a drill bit, milling cutter, or other machining tool).Actuator 120 may use shaft 122 to rotate head 124 in direction 126 aboutrotational axis 128. Actuator 120 may include a motor for rotating shaft122 and computer-controlled positioners for adjusting the location ofshaft 122 and head 124 relative to optical material 130. Followingmachining of the edges or other portions of optical structures 130,optical structures 130 may have curved surfaces such as curved surfaces132, as shown on the right-hand side of FIG. 9.

By providing optical structures in display 14 with curved edges or othercurved or angled surfaces, the optical structures may bend light that isemitted from display pixels 86 in a way that allows the light to extendlaterally outward over the otherwise inactive portions of the display.As a result, it will appear to a user of the display as if the displayis borderless or nearly borderless.

An illustrative display of the type that may use curved opticalstructures to achieve a borderless or near borderless appearance to aviewer is shown in FIG. 10. As shown in the cross-sectional side view ofdisplay 14 in FIG. 10, display 14 may include active area display layerssuch as active display structures 46A. Inactive display structures suchas inactive display structures 461 of FIG. 6 are not shown. Active areadisplay structures 46A may contain a rectangular array of display pixelssuch as display pixels 86 with a rectangular peripheral edge. Light rays44 associated with display pixels may be produced by a backlight unit(e.g., a backlight unit in a display such as a backlit liquid crystaldisplay), may be produced by light reflected off of a reflector such asreflector 80 of FIG. 5, or may be emitted by light-emitting diodestructures or other light sources within display pixels 86.

Optical structures 134 (e.g., optical structures of the type formedusing the equipment of FIGS. 7, 8, and 9 or other equipment) may beformed from transparent optical members. For example, a display may beprovided with an optical structure such as a transparent member formedfrom glass, plastic, ceramic, or other clear material. An optical membersuch as optical member 134 of FIG. 10 may have planar surfaces such asupper surface 136 (in the example of FIG. 10) and may have curvedsurfaces such as curved surfaces 138. Curved surfaces may be located onthe upper and/or lower side of optical member 134. As shown in FIG. 10,for example, curved surfaces 138 may be located in peripheral edgeportions of optical member 134 (e.g., the left and right edges of member134 and, if desired, the upper and lower edges of member 134, as viewedfrom above in direction 50 by viewer 48).

Curved surfaces 138 may allow optical structures such as member 134 toserve as light bending structures to bend light 44 from active displaystructures 46A so that the entire lateral expanse of display 14 appearsto be filled with active image content. Display 14 may, for example,appear to have no left and right borders (when viewed in direction 50)and/or may additionally have no upper and lower borders (when viewed indirection 50). The lateral dimensions (in X and Y) for active displaystructures 46A are less than the respective lateral dimensions X and Yof optical member 134, so the apparent image size for display 14 isenlarged. By enlarging the apparent size of the display, the display maybe made to appear borderless or nearly borderless, even if activedisplay structures 46A are surrounded by a border of inactive structuressuch as structures 46B.

Rays of light from active display structures 46A such as light ray 44Mare produced by display pixels 86 that are near to the center of display14. In this portion of display 14, light may travel vertically upwardsto viewer 48 without significant bending. Near to the peripheral edgesof active display structures 46A, light rays such as light rays 44E areemitted that are bent by the curved nature of the edges of opticalstructures 134 (i.e., curved surfaces 138).

As shown by the bent trajectory of light rays 44E, light rays 44E thatare emitted by display pixels 86 along the edges of active displaystructures 46A may, upon passing through optical structures 134, appearto viewer 48 as if they were emitted by display pixels located ininactive border region IA. The lateral extent (e.g., width W in FIG. 10)of display 14 over which light rays 44 are emitted and therefore theeffective size of display 14 for displaying content to viewer 48 isenhanced by the presence of curved portions 138 of optical member 134,so it appears as if display 14 has an active area of lateral dimensionW, rather than the more limited size of active area AA that isassociated with the physical size of the array of display pixels 86 instructures 46A. In this way, surface 136 can be entirely covered withactive display pixel content (e.g., graphics, text, video, etc.),providing display 14 with a borderless or nearly borderless appearance,despite the presence of display control circuitry and other inactivestructures in inactive region 461 of display structures 46 (FIG. 6).

In the illustrative example of FIG. 10, optical structures 134 havecurved surfaces 138 that are located on the lower side of structures 134near the peripheral edge of structures 134. Structures 134 may have arectangular shape when viewed in direction 50 (i.e., structures 134 maybe formed from a rectangular sheet of optical material or other planarmember with curved edge surfaces). One or more, two or more, three ormore, or four of the edges of rectangular optical structures 134 may beprovided with curved surfaces such as surfaces 138.

If desired, both the upper and lower sides of optical structures 134 maybe provided with curved surfaces such as curved surfaces 138, as shownin FIG. 11. Curved surfaces 138 may cover some or all of the upper andlower surfaces of structures 134. In the example of FIG. 11, curvedsurfaces 138 are formed in peripheral portions of optical structures134, but not in the central portions of structures 134. The centerportions of the upper and lower surface of optical structures 134 may beplanar.

FIG. 12 shows how the upper surface of optical structures 134 may beprovided with a curved (convex) shape using upper curved surface 138.The lower surface of optical structures 134 in this type ofconfiguration may be planar (as an example).

In the configuration of FIG. 13, display 14 has been provide withoptical structures 134 that have an upper surface with a planar centralregion and curved peripheral edge portions 138. The lower surface ofoptical structures 134 may be planar.

Optical structures 134 may be mounted against active display structures46A or may be mounted so that an air gap or a gap filled with materialsother than air is formed between optical structures 134 and activedisplay structures 46A. FIG. 14 is a cross-sectional side view ofdisplay 14 in a configuration in which optical structures 134 have beenmounted so that there is an air gap G between optical structures 134 anddisplay structures 46A. In FIG. 14, the center of the upper surface ofoptical structures 134 is planar. FIG. 15 is a cross-sectional side viewof display 14 in a configuration in which optical structures 134 with acurved upper surface (surface 138) have been separated from displaystructures 46A by an air gap of size G.

Optical structures 134 (e.g., glass, plastic, or ceramic optical membersof the types described in connection FIGS. 10-15) may be mounted on theexterior of device 10 or in the interior of device 10. When mounted asthe outermost structural display layer in device 10, optical structures134 may sometimes be referred to as a display cover layer or displaycover layer structures. When mounted in the interior of device 10,optical structures 134 may be covered by one or more additional layersof transparent material such as a display cover layer and/or otherlayers of clear material.

FIG. 16 is a cross-sectional side view of display 14 in an illustrativeconfiguration in which optical structures 134 have been covered byadditional optical structures such as display cover layer 140. Displaycover layer 140 may be a layer of transparent material such as a clearlayer of plastic, glass or ceramic (as examples). Light bending opticalstructures 134 of FIG. 16 have been formed from glass, plastic, or otherclear material with a shape that exhibits a triangular cross-section(i.e. a shape with sloped surfaces 138). Sloped surfaces 138 may formplanar or non-planar curved surfaces for bending light. Air gap G mayseparate the lower surface of display cover layer 140 and the uppersurface of display structures 46A. Optical structures 134 of FIG. 16 mayrun along the right and left edges of display 14 (e.g., make display 14appear borderless along its right and left edges), may run around theentire periphery of display 14 (e.g., structures 134 may have arectangular ring shape with a central opening that makes display 14appear borderless along all four of its edges), or may be configured tocover other portions of the edges of display 14.

As shown in FIG. 17, optical structures 134 may be provided with opticalcoating layers such as layers 142. Layers 142 may be formed fromdielectrics such as sputtered oxides, from clear materials depositedusing physical vapor deposition, chemical vapor deposition, or otherdeposition techniques (e.g., coatings of glass, polymer, ceramic, orother materials), or may be formed from other transparent coating layerson optical structures 134. There may be one or more layers 142, two ormore layers 142, three or more layers 142, or four or more layers 142.Layers 142 may include layers such as antireflection layers, antismudgelayers, antiscratch layers, or other layers to modify the properties ofthe upper and/or lower surface of optical structures 134.

It may be desirable to use optically clear support structures such aslayers of cured clear adhesive (transparent solidified liquid polymer)to support optical structures 134. As shown in FIG. 18, for example,device 10 may have a clear polymer layer such as polymer structure 144for supporting optical structures 134. Components 146 may be mountedwithin housing 12. Display structures 46 may be mounted on supportstructures such as portions of housing 12 or other structures. Toprovide display 14 with a borderless or nearly borderless appearance,optical structures 134 may have curved surfaces such as curved surfaces138. Polymer material 144 may be formed from a cured optical adhesive(e.g., optically clear adhesive). Initially, when in an uncured liquidstate, polymer 144 may be placed on top of display structures 46 (e.g.,by dripping, screen printing, spraying, etc.) Optical structures 134 maythen be placed on top of the liquid polymer. Ultraviolet light curing orthermal curing techniques may then be used to cure the polymer materialto form solid polymer support structures such as structures 144 of FIG.18.

Structures 144 of FIG. 18 may support optical structures 134 and mayhold structures 134 at a desired distance from display structures 46such as active display structures 46A and may help attach opticalstructures 134 to device 10. Polymer material 144 may, if desired, havea relatively low index of refraction compared to the index of refractionof optical structures 134. For example, optical structures 134 may beformed from a material such as glass with an index of refraction of 1.4or above (e.g., 1.4 to 1.8), whereas polymer material 144 may have anindex of refraction of less than 1.4, less than 1.3, less than 1.2, orless than 1.1 (e.g., 1.0 to 1.2). In this way, polymer material 144 maybehave optically as an air gap, allowing light 144 to be benteffectively by curved surfaces 138 of optical structures 134.

FIG. 19 is a cross-sectional side view of device 10 in a configurationin which curved surfaces 138 of optical structures 134 have been formedon the lower surface of optical structures 134, adjacent to solidifiedliquid polymer material 144.

In the illustrative configuration of FIG. 20, optical structures 134have been covered with a layer of transparent material such as displaycover layer 140. Display cover layer 140 may be a planar sheet of glass,plastic, or ceramic. Optical structures 134 may have a planar uppersurface such as upper surface 136. Angled edge surfaces 138 may lie inplanes that are not coplanar with upper surface 136 to allow the edgesof optical structures 134 to bend light from display structures 46. Airgaps such as gap G may separate optical structures such as opticalstructures 134 of FIG. 20 or other optical structures 134 from displaycover layer 140 and/or polymer such as polymer 144 may be interposedbetween display cover layer 140 and optical structures 134 and/orbetween optical structures 134 and display structures 46.

If desired, device 10 may be provided with touch sensor functionality. Atouch sensor for device 10 may be implemented using an array ofcapacitive touch sensor electrodes (e.g., transparent conductiveelectrodes such as indium tin oxide electrodes), may use resistive touchtechnology, light-based touch sensors, acoustic touch sensor technology,or other touch sensor technology. As an example, a capacitive touchsensor for device 10 may be implemented using a one-sided or two-sidedarray of indium tin oxide electrodes. The electrodes may be formed on atouch sensor substrate such as a layer of glass or plastic that isseparate from other layers in display 14 (e.g., a touch sensor substratethat is mounted within display 14 using adhesive) or may be formed onthe surface of optical structures 134, display cover layer 140, or otherstructures in display 14.

FIG. 21 is a cross-sectional side view of display 14 in a configurationin which touch sensor 146 has been formed on the lower surface ofoptical structures 134. An air gap or polymer gap may separate touchsensor 146 from display structures 46A. Touch sensor 146 may includecapacitive touch sensor structures such as a one-layer or two-layerarray of indium tin oxide electrodes. The indium tin oxide electrodesmay be formed directly on the lower surface of optical structures 134 ormay be formed on a substrate (e.g., a sheet of glass or polymer) that isattached to the underside of optical structures 134 by adhesive (asexamples). An air gap or a gap filled with polymer 144 may separatedisplay structures 46A from touch sensor 146.

In the illustrative configuration of FIG. 22, touch sensor 146 has beenformed on the surface of display structures 46A (e.g., by attaching atouch panel with a thin glass or polymer substrate to display structures46A with adhesive).

FIG. 23 is a cross-sectional side view of display 14 in a configurationin which touch sensor 146 has been formed on the upper surface ofoptical structures 134. Touch sensor 146 may have portions that are bentto conform to the shape of curved surfaces 138 of optical structures134.

FIG. 24 is a cross-sectional side view of display 14 in a configurationin which touch sensor 146 has been formed on the upper surface ofoptical structures 134 and in which device 10 has a display cover layersuch as cover layer 14. Cover layer 140 may be separated by an air gapor a gap filled with polymer 144 from touch sensor 146 and opticalstructures 134.

FIG. 25 is a cross-sectional side view of display 14 in a configurationin which touch sensor 146 has been formed on the underside of displaycover layer 140 (either as layers deposited directly on display coverlayer 140 or as a touch panel that is attached to display cover layer140 with adhesive). An air gap or a gap filled with polymer 144 mayseparate touch sensor 146 of FIG. 25 from optical structures 134.

The foregoing is merely illustrative of the principles of this inventionand various modifications can be made by those skilled in the artwithout departing from the scope and spirit of the invention.

What is claimed is:
 1. An electronic device, comprising: a transparentdisplay cover layer having opposing inner and outer surfaces, whereinthe inner surface comprises a flat portion that defines a plane and acurved portion that curves out of the plane; a display layer comprisinga plurality of pixels, wherein the plurality of pixels emits lightthrough the transparent display cover layer, wherein the transparentdisplay cover layer redirects a portion of the light through the curvedportion; and a housing having a rear surface and sidewalls that extendfrom the rear surface, wherein the curved portion of the inner surfaceoverlaps the sidewalls.
 2. The electronic device defined in claim 1wherein the plurality of pixels have a first width, the transparentdisplay cover layer has a second width, and the second width is greaterthan the first width.
 3. The electronic device defined in claim 2wherein the curved portion of the inner surface is configured toredirect the light to have a width that matches the second width of thedisplay cover layer.
 4. The electronic device defined in claim 3 whereinthe transparent display cover layer is adhered to the housing by a layerof transparent polymer.
 5. The electronic device defined in claim 4wherein the layer of transparent polymer extends from a first sidewallof the housing to a second sidewall of the housing.
 6. The electronicdevice defined in claim 1 wherein the curved portion of the innersurface is convex.
 7. The electronic device defined in claim 1 whereinthe housing further includes portions that extend from the sidewalls,and the display layer is coupled to the portions that extend from thesidewalls.
 8. The electronic device defined in claim 7 wherein theplurality of pixels is formed in an active area of the display layerthat is surrounded by an inactive border region of the display layer. 9.The electronic device defined in claim 8 wherein the curved portion ofthe inner surface of the transparent display cover layer, the layer oftransparent polymer, the inactive border region of the display layer,and at least one of portions of the housing that extend from thesidewall all overlap.
 10. The electronic device defined in claim 9further comprising: a touch sensor layer interposed between the displaylayer and the inner surface of the transparent display cover layer. 11.An electronic device, comprising: an organic light-emitting diodedisplay layer having an active area that emits light and that issurrounded by an inactive border region; a housing having a back surfaceopposite the organic light-emitting diode display layer, wherein thehousing comprises sidewall portions that extend from the back surface toform support structures on which the inactive border region rests; atransparent display cover layer that has first and second opposingsurfaces, wherein the first surface has a flat portion that defines aplane and overlaps the active area, wherein the first surface has acurved portion that curves out of the plane and overlaps the inactiveborder region, and wherein the transparent display cover layer redirectsat least some of the light emitted by the active area to the curvedportion over the inactive border region; and a transparent layerinterposed between the active area and the transparent display coverlayer, wherein the inactive border region of the organic light-emittingdiode display layer, at least one of the sidewall portions of thehousing, the curved portion of the transparent display cover layer, andthe transparent layer all overlap.
 12. The electronic device defined inclaim 11 wherein the first surface is an inner surface that faces theorganic light-emitting diode display layer, and the second surface is anouter surface.
 13. The electronic device defined in claim 12 wherein thecurved portion of the inner surface is convex, and a part of the convexcurved portion overlaps the organic light-emitting diode display layer.14. The electronic device defined in claim 13 wherein the transparentlayer is a layer of optically clear adhesive that adheres the organiclight-emitting diode display layer to the inner surface of thetransparent display cover layer.
 15. The electronic device defined inclaim 14 wherein the transparent display cover layer has a first indexof refraction, and wherein the layer of optically clear adhesive has asecond index of refraction that is less than the first index ofrefraction.
 16. The electronic device defined in claim 12 wherein thecurved portion of the first surface of the transparent display coverlayer, the transparent layer, the inactive border region of the organiclight-emitting diode display layer, and the support structures of thehousing overlap each other.
 17. The electronic device defined in claim16 wherein the transparent display cover layer has a first width andwherein the organic light-emitting diode display layer has a secondwidth that is smaller than the first width.
 18. The electronic devicedefined in claim 17 wherein the curved portion of the transparentdisplay cover layer is convex to guide at least some of the lightemitted by the organic light-emitting diode display layer to have aviewable width that is greater than the second width.
 19. An electronicdevice comprising: a housing having sidewalls; a display layercomprising an array of pixels that form an active area and comprising aninactive border region that surrounds the active area; and a transparentoptical member that forms an outermost surface of the electronic device,wherein the transparent optical member has an inner surface with convexportions and an opposing outer surface, and wherein the convex portionsoverlap the sidewalls of the housing and the display layer.
 20. Theelectronic device defined in claim 19 wherein the convex portions of thetransparent optical member are configured to guide light emitted by thedisplay layer to a portion of the outer surface of the transparentoptical member that overlaps the inactive border region of the displaylayer.